Inertia compensating device



Dec. 22,1942. R/KQTHOMPSON 2,305,912 I INERTIA COMPENSATING DEVICE Filed Aug. 3, 1940 ./P0 saver K flaw/25a INVENTOR Patented Dec. 22, 1942 UNITED STATES PATENT OFFICE INERTIA COMPENSATING DEVICE Robert K. Thompson, Detroit, Mich., assignor to George M. Holley and Earl Holley Application August 3, 1940, Serial No. 350,979

4 Claims.

come effective, the fuel surges down and expands the diaphragms in the diaphragm chamber, temporarily cutting off the supply of fuel, the engine cuts out and there is some danger of a forced landing taking place, although the chief difficulty is that there is a delay in the engine up power after the power dies.

The drawing shows diagrammatically the application of this invention to a well known type of carburetor. 2,088,464, 2,230,144, 2,228,000 and 2,232,392.

In the drawing, 15 is the air entrance, I is the mixture outlet leading to a supercharger I0| connected through a pipe I02 to the inertia device which is the subject of this invention which is contained in a chamber I03 which contains the weight I04 supported by a spring I05 and carrying a needle I06. The function of the spring I05 is to raise the weight I04 and seat the valve I06 so as to close the opening from the pipe I02 to the chamber I03. The pipe I01 connects the chamber I03 with the chambers 25 and 26 which are connected through the pipe 26 with each other. These chambers 25 and 26 are adjacent to the diaphragms I9 and 20. Hence, when the valve [06 is thrown off its seat by inertia forces, the supercharger pressure is transmitted from the pipe I02 through the chamber I03 to the passage I01, and thus the pressure applied to the diaphragms 26, 25 is increased by the pressure from the supercharger I0l. The head on the fuel in the chamber 21 is thus increased.

If it were not for this device the following would be the result of inertia forces: The fuel in the chamber 21 would be thrown downwardly and thus would exert lateral forces on the diaphragms I9 and 20. The needle valves 34, 35 would thus be held closed and the fuel flowing through the fuel entrance 63 would be disconnected from the fuel chamber 21, so that fuel would cease to flow past the needle 29 down the passage 30 and out of the outlets 44.

The rest of the carburetor needs only to be briefly discussed as it is no part of this invention, being illustrated merely to show the compick- This is covered by U. S. Patents plete device to which this inertia apparatus is applied.

A fuel pump 32 with the usual pressure regulating bellows 36 and relief valve 31 supplies fuel through a passage 63 to a venturi 93. When the flow through this venturi exceeds a predetermined maximum determined by the spring 11, the diaphragm 38 forming the right hand Wall of the chamber 18' moves to the left and opens the valve 39, admits fuel to the passage 40, which discharges into another passage 4|, which discharges through a pipe 42 into the variable venturi formed between the two throttles 43, 44. A small quantity of air is admitted tothe fuel issuing from the passage 40, through the air opening 9|.

On the other side of the venturi93 two pipes 6 I 62 transmit the two pressures in the fuel line to the chambers 60, 59 and so cause the-diaphragms 51, 58 to move to the left when the fuel exceeds a predetermined maximum as determined by the spring 12. When these diaphragms 51, 58 move to the left the valve 66 closes the passage 56 and thereby nullifies the effect of the mixture control valve 5| controlled by the lever 52.

This valve 5| contains a restriction 53 which communicates through the passage 54 with the passage 30 and thus transmits vacuum from the throat of the variable venturi formed between the throttles 43, 44 to the chamber 61 which communicates with the passage 24 and. thus transmits suction to the chambers 25, 26.

The effect of the movement of these diaphragms 51, 58 to the left is that in the event the lever 52 is in the cruising lean position as shown, the moment the fuel flow exceeds of the maximum fuel flow, then the valve 66 closes and the mixture is restored to the cruising rich mixture ratio.

The altitude control is shown immediately to the left of the carburetor and comprises a barometric device I0 consisting of an exhausted bellows connected through a link I I, pin I2, lever I9 mounted on the fulcrum I4, the lever I9 engaging through a pin I1 with a fork I8 which carries the slide valve 2| which controls the restricted opening 22 which communicates with the passage 24. The movement of the valve 2| is controlled by the spring 14 which is adjusted by means of the adjusting screw 13. The other end of the lever I9 is controlled by the movable fulcrum I4 located on the end of the rod I5, and

the location of the rod I5 is determined by the adjusting screw I6. The variable venturi is formed between the throttles 43, 44, which are geared together by the gears 45, 46 which in their turn are geared to the gear 80 which is mounted on the cam 65 which is manually rotated in an anti-clockwise direction when the throttles are opened.

The counter-clockwise rotation of the cam 65 causes the lever 68 to move clockwise, stretching the spring 8| and moving the ball end 69 of the lever 68 and thus moving the needle 29 to the right and admitting more fuel from the chamber 21. A low speed passage 48 is shown communicating with an annular chamber 49 which communicates with the passage (in the center of the needle) 41 which provides the air for low speed running. An air vent 59 is provided for normal running and it admits air at all times to the passage 3!], whereas the low speed air which regulates the idling mixture is only admitted when the throttles are practically closed.

Lateral inertia forces acting on the diaphragms l9 and 20 have a tendency to cause one valve St to open, at the same time the inertia forces tend to close the other valve 35. Hence with the arrangement shown, inertia forces, both vertical and lateral, are compensated for so that the carburetor does not restict the possible maneuvers of the pilot.

What I claim is:

1. In combination with an internal combustion engine for an airplane, a supercharger connected with the engine, a carburetor of the type in which a diaphragm is used to control the head on the fuel, said carburetor being connected to the air inlet leading to the supercharger, and means adapted to reciprocate vertically with reference to the direction of motion of the plane responsive to inertia forces less than the maximum gs. to which the pilot may be subjected and greater than 2gs. created by the maneuver of the plane for superimposing the supercharger 0 pressure on said diaphragm for the purpose described.

2. In combination with an internal combustion engine for an airplane, a supercharger, a carburetor connected to the air inlet leading to said supercharger, said carburetor having a fuel supply chamber, an air chamber in equilibrium therewith so that the pressure in said air chamber determines the flow of fuel in said carburetor, a passage connecting the pressure side of the supercharger with said air chamber, a weighted valve reciprocating in said passage at right angles to the direction of motion of said plane, a spring means for seating said valve, and means responsive to inertia forces less than the maximum gs. to which the pilot may be subjected and greater than 2 gs. adapted to unseat the valve and to thereby increase the pressure in the said air chamber.

3. In combination with an internal combustion engine for an airplane, a supercharger, a carburetor connected to the air inlet leading to said supercharger, said carburetor having a fuel supply chamber located between two vertical diaphragms, having fuel inlet valves controlled thereby and an air chamber associated with each diaphragm and with each other, a passage connecting said air chambers with the pressure side of said supercharger, a weighted valve reciprocating in said passage at right angles to the direction of motion of saidjplane, spring means for seating said valve, and means responsive to'inertia forces less than the maximum gs. to which the pilot may be subjected and greater than 2gs. adapted to unseat said valve and to thereby increase the pressure in said air'chambers.

4. In combination with an internal combustion engine for an airplane, a supercharger connected with the engine, a carburetor of the type having an air chamber in'which a diaphragm is used to control the head on the fuel, said chamber being connected to the air inlet'leading to the supercharger, and means responsive only to the inertia forces less'than the maximum gs. to which the pilot may be subjected'and greater than 2 gs. acting at right angles to the direction of motion of the plane in effect when pullingoutof a dive for superimposing the supercharger pressure on said diaphragm for the purpose described.

ROBERT K. THOMPSON. 

